The discussion about the Kochs’ financial contribution to Heritage Action comes as the group is pushing Republican lawmakers to make defunding Obamacare a provision in a deal to fund the government and raise the country’s debt ceiling.

Heritage Action’s position is at odds with Koch Companies, which moved Wednesday to publicly tell lawmakers that while it believes Obamacare will increase deficits, raise taxes, among others things, it isn’t pushing lawmakers to include defunding Obamacare in a government funding package.

“Koch has not taken a position on the legislative tact of tying the continuing resolution to defunding Obamacare nor have we lobbied on legislative provisions defunding Obamacare,” Philip Ellender, president of government and public affairs at Koch wrote in a letter sent Wednesday to senators. “Instead, Koch has focused on educating the public about reducing our nation’s debt and controlling runaway government spending.”

Heritage Action later said the contribution was made through Freedom Partners.

The discussion about the group’s donors, which are not publicly available, came after Needham said Heritage is helping the conservative base have a voice in Washington and be a counterpoint to K Street and business.

Specifically, Needham pointed to House Republicans’ decision to attach the repeal of the medical device tax to a spending bill before the government shutdown as a corporate giveaway. Heritage Action Fund publicly opposed that decision when the bill came up for a vote.

Needham declined to name any other donors, saying the group’s tax status doesn’t require that it disclose.

Under intense questioning, Needham conceded that the group is “not being transparent” with its donors, though he noted it follows the law.

He confirmed that Heritage Action does take corporate contributions but said that it made up less than 5 percent of its overall donors.